Thursday, October 27, 2005

Tempo and Mode

The original "Gould on the Beach" (see below) story has generated a fair amount of attention from evolutionary blogs (e.g. Panda's Thumb, Evolutionblog, Dispatches from the Culture Wars, Red State Rabble). Most of the posts have justly castigated the inanity of Pivar's and O'Leary's comments. Gould was certainly no friend of intelligent design creationism, and no amount of quote mining will make it so.

However, it does not automatically follow that Gould was "clear, consistent, and unambiguous" on the subject, as Jason Rosenhouse (and others) have suggested. At least his thinking was never that clear to me. I hate to admit it, but I think that Gould was indeed something of an "equivocator" as Dembski suggests (without noticing the irony of such a charge, apparently). Since others seem to be oblivious to this aspect of Gould's thinking, I should illustrate what I have in mind.

Here is Gould at the height of his powers, writing about saltation in his classic "Is a new and general theory of evolution emerging?" (Paleobiology 6, 119-30; 1980):
[...] the other alternative, treated with caution, reluctance, disdain or even fear by the modern synthesis, now deserves a rehearing in the light of renewed interest in development: perhaps, in many cases, the intermediates never existed. I do not refer to the saltational origin of entire new designs, complete in all their complex and integrated features -- a fantasy that would be truly anti-Darwinian in denying any creativity to selection and relegating it to the role of eliminating old models. Instead, I envisage a potential saltational origin for the essential features of key adaptations. [...] Yet Darwin, conflating gradualism with natural selection as he did so often, wrongly proclaimed that any such discontinuity, even for organs (much less taxa) would destroy his theory.
(Note how he directly contradicts the statement attributed to him by Pivar.) This is typical of Gould's writings of the time, where he tended to muddle the time scale over which to apply his punctuationism and Darwin's natura non facit saltum. In the end, we're left wondering over exactly what is being proposed that would require the emergence of a "new and general theory", if it isn't Goldschmidtian "hopeful monsterism" (I sense a new religion coming...).

In the same paper he also discussed whether macroevolution can be explained by extrapolating from microevolutionary processes, another of Gould's leitmotivs from that period:
But if species originate in geological instants and then do not alter in major ways, then evolutionary trends cannot represent a simple extrapolation of allelic substitution within a population. Trends must be the product of differential success among species. In other words, species themselves must be inputs, and trends the result of their differential origin and survival. Speciation interposes itself as an irreducible level between change in local populations and trends in geological time. Macroevolution is, as Stanley argues, decoupled from microevolution. [...]

As a final point about the extrapolation of methods for the study of events within populations, the cladogenetic basis of macroevolution virtually precludes any direct application of the primary apparatus for microevolutionary theory: classical population genetics.
I believe that essentially all macroevolution is cladogenesis and its concatenated effects. What we call 'anagenesis' and often attempt to delineate as a separate phyletic process leading to 'progress,' is just accumulated cladogenesis filtered through the directing force of species selection [...]
(My emphasis. Bibliographic references removed.)

Not exactly an endorsement of natural selection's ability to shape macroevolution, is it?

Read on

Tuesday, October 25, 2005

Gould on the Beach...

Now, there's an opera I wouldn't mind seeing! It could be written entirely with passages from his "Natural History" essays. It would have leitmotivs for "contingency" and "constraint", "Bauplan" and "Baseball"...

Andrea Bottaro, over at The Panda's Thumb, brings us a particularly bizarre example of second-hand Gould exegesis, bordering on channeling. A certain Stuart Pivar, ominously described as "a chemical engineer as well as an art collector", thinks of himself as something of an authority on Gould "because Gould used to spend time at his beach house"! Apparently Pivar believes that Gould would never have "signed the statement of the National Center for Science Education’s list of Steves" because:
His message was that natural selection was merely an eliminative force with no creative role, capable of choosing for survival among preexisting forms which are produced by other natural structural processes.
This is, of course, utter nonsense, as Andrea demonstrates in his post. He concludes that:
In other words, Gould saw structuralist principles, together with the role of contingency and developmental contraints, as applying on top of a solid Darwinian theoretical foundation, not to supplant natural selection as a major creative force in evolution, but to influence its outcome. This is a view consistent with the Steves' statement, and most certainly shared, with accommodations for varying emphasis on this or that aspect, by the vast majority of modern biologists.

For those who have read Gould's primary scientific works this is really nothing new, since - misunderstandings and histrionisms aside - his views on the matter did not change very much over time [...] his legacy as a scientist should be found in his own articles and books, not on the web site of some beach buddy, no matter how close.
Although I agree with the main points of Andrea's post, I would be more guarded in my evalutation of Gould's thinking. On this subject, Gould was often insightful and provocative, but was certainly not a model of clarity, as even a cursory inspection of his massive "Structure" will reveal. Although his "message" was emphatically not "that natural selection was merely an eliminative force with no creative role", he did show a longstanding ambivalence towards natural selection, and ostensibly attempted to demote it (subjugate it, even) relative to other forces, such as, contingency, constraints, or species selection.

Not only did Gould have a "penchant for staking debates in rather extreme terms, and sometimes caricaturing his opponents’ positions", as Andrea puts it, but he was often hard to pin-down on his positions. For example, in his writings on punctuated equilibrium he repeatedly equivocated on the time scale he had in mind when contrasting punctuationism and gradualism, to the frustration of his critics. As he well knew, "fast" does not mean the same thing in terms of generation or geological time. Gould would echo Goldschmidt's attacks on the modern synthesis, and would then be extremely vague on the nature of the putative novel genetic / evolutionary mechanisms that needed to be incorporated into evolutionary theory to account for punctuated equilibrium. Similar objections can be (and have been) raised to his writings on adaptationism and the Cambrian explosion. Critics of evolution have been quick to exploit these inconsistencies in Gould's thinking. For example, much of the nonsense spouted by creationists of all stripes on the distinction between micro and macroevolution can be traced directly to "misunderestimations" of Gould's primary articles.

Even if Gould did not usher in the emergence of "a new and general theory of evolution", as he would have liked (time will tell), I still think there's an opera in there somewhere. Maybe PhaWRONGula will take up the challenge...

Read on

Sunday, October 09, 2005

The Other Prize

After the prizes from Stockholm all scientists dream about, it's time for their light-hearted counterpart, the Ig Nobel Prizes. Sir Bob May (of "chaos" fame) will probably be even more upset this time given the enviable performance of scientists from both Australia and the UK.

One of my favorites is the Peace prize:
Claire Rind and Peter Simmons of Newcastle University, in the U.K., for electrically monitoring the activity of a brain cell in a locust while that locust was watching selected highlights from the movie "Star Wars." (Rind FC & Simmons PJ, 1992. Orthopteran DCMD Neuron: A Reevaluation of Responses to Moving Objects. I. Selective Responses to Approaching Objects. Journal of Neurophysiology 68, 1654-66.)

Read on

Saturday, October 08, 2005

Good things...

This made me laugh.

(OK, OK, the dolphins are off, but it's still pretty funny...)

Read on